A colour revolution uses legitimate griefs people have with their government to co-opt the movement and promote regime change instead for foreign interests that fund the revolution.

For example a colour revolution is currently attempted in Cuba by mobilising the diaspora who, in turn, mobilises the Cuban population. The embargo is hitting Cuba really bad (cost 60 billion dollars since 1960) and this prevents them from having much-needed medical supplies (especially against covid), cheaper internet access or just more consumer goods.

That's a legitimate grief that has led to some unrest sometimes -- even if the embargo is not Cuba's fault and is literally only supported by the USA and Israel. But it's being weaponised by the United States and they're funding protests in Cuba so they can point and say "look, people don't want the communist party in charge! They're protesting for more freedoms!". What was originally "we're tired of not having these simple things, please give us them and we will stop picketing" now has turned into "we will topple the government and throw molotov cocktails at the police".

The pattern of a colour revolution is: foreign funding -> local "leaders" -> protesting masses. Foreign powers start funding and even sometimes training people who align with their interests and they put them to work for co-opting protests to promote regime change. Sometimes the people that are funded are not really leaders and locals didn't even know them until they suddenly took an interest. Sometimes protests are started by bought locals. The common point is that they're using legitimate unrest to ask for something else entirely.

Colour revolutions were and still are a favourite of the CIA because you can't really trace it back to them (not in time at least) and all it takes them is money and meeting with locals. It also creates a ton of support at home because the protestors want "freedom", and who doesn't want freedom? What kind of monster is stopping their people from wanting freedom? And if the targeted government retaliates against the protestors in any way, you can also say "look they're putting down the protests, these people just want democracy why is the government so afraid of giving it to them?". But they don't want democracy, they want regime change. They want to install a neoliberal government that will let their natural resources be exported by American companies.

So the CIA funds loyal people and if the protest doesn't work out, they were never there. That's the genius of it. All you have are receipts through front companies (because the leaders are paid for mobilising people against the government) and it's the protest leaders that get arrested, not the American agents. This means you can try again with another patsy if your fall guy gets busted.